SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9317bbc675707a48dec3403e16f9fbb80059cfb750232c5af9d50f7cb861362' 
  AND token = 'mWBnnVgKjfKwOgV4PkY/UtDVVfXghqDpmvBN+3t2FkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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