SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed27b8b706cbc28a084182901e59cc4d9ce7e7322f6ed26cc0a1fc5039463b5' 
  AND token = 'EwaHeKqvq0biQb2JROYsgOg2Sf+PzhMvr/OQ9Z6YQ2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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