SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad0fe53e30bf29ce771408a381514d275535f61eedc0c1ed64f552f6b3abe59' 
  AND token = 'y6MmMVTXbRltm6dAsvwiSFP7p68i6Z9fT0MLRNrFRAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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