SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e58488c8ae42de11aa8a65732791733bc935816ecba8ebe2ce2b112f4ce4522' 
  AND token = 'y9wLc6OdHrVC2FoAucQFJFcfnaxw4ULPXwgvIgf3T6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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