SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4d6e8bc77325b86edd32c01c28fa21dce64e4cc30cb6116a7bd1d84791ea0b14' 
  AND token = 'zEyUKiJlcCcRWYMXn0j3XHTxx9pZZ8QNUiktlMgZqaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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