SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d7f04beac5bcb1d1f216f83b3eed47c1d0b43e6a169fe15a524ece7f81405bc' 
  AND token = 'RGqSqwJCpTcPGupK72ZfvFrh56NsO7gc9XzvZPPFhvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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