SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'daa087f4c588288f1aad8f6e21791e2371a6d1a768351f320683c5249eda14b0' 
  AND token = 'smZq50rpVqyHRUuJkhEDP2xXwPyyTdI1UG2QqwwBJLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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