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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6edc85ca65d7f6c87392d6ac4442e0c5e0068ab67ee481f09857365e939bc3c6' 
  AND token = 'SmN9QSuhEmm6+uz+Ahpz990VFaeunveJYhVsveR/hDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}