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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f4cbd57b50ac476244a9ece6952dfafca7f5765ee48d088b7afa0f4eeed7ed4b' 
  AND token = 'r9+RCnXGiYeOjwEJavq0gZ0ZvK/wilLUYKgRMx6Exik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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