SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c5e3376fe80d58b2802e63e6a33644430af7a12d6cd91ae2071b8f201641c3b' 
  AND token = 'VZEYwYqm20OGvzWeII/vlViFzSMt46m15080b2brX5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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