SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd540f2a9fddc50bed4b0a28a8a475022bc026d416a2175dfcdb5130956ad6a9b' 
  AND token = 'pTKZqTGxDIZgpsttzh+RMm92YPltVnnDvAbqEArvybU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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