SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef3a70066af304c38cd0eceaa786f08a5f7f7eb48a3a8370c1554c0438be12b5' 
  AND token = 'nCRiCjlgfp0j7L4pQBF9HQiLsib1XOOR/+w1WGaQ3KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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