SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4f4918663e29f71eb8de91930660da8c2b1c66159cfc67f302bd1ddf5d2bfb4' 
  AND token = 'kmoyq6CzKgdZgEgU+2BBBEZFe0/FyKKTBKc9fbnV7O8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}