SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a29066c3d891ef0f679a011203d0c7233573f22f71d3d370ea6826a5b01e3a6f' 
  AND token = 'a7Qcf18hPRJ3oB+p75HWI7wVBwCGJd+9qjrVw+ZVdj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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