SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92622f7c785231551fae48ea1db10985e03ea6644b7cf287fe68a1109995be0b' 
  AND token = 'btwiSAwPEA/znKL07u0CfPvJyTKMCn3dxwJ2exTVSHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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