SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '601abeb963119654c288ecdabc409357f78ea6a55f018a53631b54c20f29362d' 
  AND token = 'n4gfwCp+rsa3axWmy8Ueu2Rp54vp5bfCp920EHPUoC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}