SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd28809602fa95df92500a5ac6ef2e5a058260a5eae2ea490889fe860e3a8137b' 
  AND token = 'tZRjTbzYvv+IM0itHO0zhawaG/SbihLNc69uWrLsb00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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