SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eac4d06871cf90967d2b1b68b434287d7e841f408cc1d918fe4710fcfbe4361' 
  AND token = 'ZtnBYwJQTBjOVlcJKmuPd3wor1ARrqoRMZpBH+AziUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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