SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785a3929d5146d8f0cac8b79ca4324d03ae2332aba74fd3323d2b44af5f18b02' 
  AND token = 'P7LEn6MOKEoLu7CbPDNhXvdw3nh86r1/lV3mvyKiLNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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