SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd1b2a562b700a03a5530aec288741d174aa29c094dba68a317b0c8f0d2ea64a' 
  AND token = 'JVL0S8VFbUHqjA65zzNxmyCE7t5e7MBYx7JaUcxWTh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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