SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f983af46c6669cada8a460b473f40a07a6b20f2395471a3aa90beab6859145b1' 
  AND token = 'H3F1jOhpJMAH0pQbq93X4qHzubDbqaP0Ewax0kjVnxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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