SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2f962c3fdb95b217dff21dab4fe7e1ffbd136c0730fc428598e680429aefa17' 
  AND token = 'fk/6hZRwvV7zT5DwgFoFKpDxDiiLmzTfCR9UdSxFjrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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