SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e5b666d06c62e86ec0c178c621ee91ed867191b056f9c3ad490844fe75d442e' 
  AND token = '2P7MLbYY83RWH61WPHNHhBmD53aJKdN5daP5pHCz2jU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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