SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '223682182652a29190fc4641646a03490079bb6cb1dfa30235acfbc8abc942ed' 
  AND token = 'NMN6eqsDF6gmVilub0TrJ1JbEeknSxYZtnhrnj3myjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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