SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dcfa09702e38a016c0fac7491335035bd88a37bb62092412ba40736ef82024' 
  AND token = 'wmTyk3MKE8D4THrD93aKih/jckthf+mvGJ24nvwLriI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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