SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8e240b386bbc3c5db8d361f04e0a7d983481a461f8de9245a45aa64247d2d7b' 
  AND token = 'BlX6YJ/tKEsm8Nauxqs4QcvzmO0bYEGGHWhzAiPNVj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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