SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae31415b3fde329d62ad1707998628c2cf606107c48fdaf3c586882b0bc3eddd' 
  AND token = 'RXrXKHsS6pNVb4I48b5+Zj/SuXL9+t+dw/KgHwIKLCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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