SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '877a094b853681fe64f6766b9202632d1991a3dbd6d15e52ef11d57dc2d8e0cd' 
  AND token = 'ynWZMNu7Brt4syskTJevH2lnXCrddkHOTfyIG5Tkzbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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