SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db29fe9583f7ca9c66677cbc71327a9677ccaa3261100e1fae0c4f74879d78a5' 
  AND token = 'ufuLoDb9L8Coggqzwi2L/Nx6EcFOxTDxzQO2hRwblXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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