SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f51a910e5b3db13698c01f349f1cd058c80bdf6899ac9840dd164f3c36ddcc6' 
  AND token = 'FbkNULZuPZb/Y0c+IfEmfRBiJ9Vls5z1Zs3zLtzuPPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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