SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a45f22aa774bca8a5811f4e02643006b8a3a55959bf27a71f134b32cb3072948' 
  AND token = 'q/rW8PuRUzRvVwEC4IJ+Dud3Xw1YpusWBo/KQYn56g0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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