SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a833645264ae077d81a55b23d5e15d85e23b5aa784a5a82fc20c1668acc0b951' 
  AND token = 'V+Fy0EQlO5BNs44plvHByCHYXaHcZH+CObT5YAShjKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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