SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc79ea9793d15c666d1590d3a1679e899a741e499bae46768258519d6fa76531' 
  AND token = 'Oma/VpYfnJldwHnMBWnXREbDBdQ4271vS/8hew2xL6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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