SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e78201aa8cacf33ce602a268891d506a9c636b666cb98a3c147c5109b5291c' 
  AND token = '95NJsdB2D3nmkLoSGNlAGBWTGXieyEBlJMZwVyyBkr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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