SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385d113e2df55c3872c748046f745b45b5856407a193e3d2ef422dc015a896eb' 
  AND token = '6BuLBLzR33iDnbRqNClkyiZd8kc9ILThKiKC652zthw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}