SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15584533bf3e73df206319a5a3a9d30695403e56249074756f697d3c9752a282' 
  AND token = 'K1SmU7jpuuGo+9J7Ttvfp4v+XpGSOiY2L7qqICTDJsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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