SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '624c89cc0cb963ba9cebefd225d44f1a7ca0020ff205b9ea93b2652ee0576027' 
  AND token = 'CCXymAI6eVtFQAj2ySDl0oBIAV1qAjZ37KkaK1kVyv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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