SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e8ab901d261684df00b09b1d12f2a548285f4aa45e05225cf44afcbbe6556a1' 
  AND token = 'YbyjzZWd4DjFlMo7EW0SybBrNRHUpfeZQouuaP7EmzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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