SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45d2d1408a899340706f7cd0330d128858c07b12c4ffa359eeef04db5aa0cb68' 
  AND token = 'MIIkMmoqCljqEWNiv3l42wBvPElqbZ7aXYCpbybbB5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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