SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395a74553686f95887bd45fab4895cdf0df30a2b25d92cd86c361bf4a5574d88' 
  AND token = 'tCwynOsOBa9QF+2kXOgYzZ8R8qo5RvY75B5NCPuFmvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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