SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb26c1da2899209e4fb7569c651daa688e82b429a82e31ed2c92973990bd018' 
  AND token = 'RBljhZPLD4gYv+z2HaFDOAV5A/g5VrL7R8Fo4sYFWQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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