SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e9430bc51540265f80afbf08a3d22087198b18fafae78ad064029c425dd8aee' 
  AND token = '191Xho1z8p0uRXuBY6FgLUye0GXDb3eiXYD7GRyV5oY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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