SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00b6406da77badaed1519aef1b2a4b1cfbb3370ddcb261f0e74fa2e822d037e7' 
  AND token = 'Kc61+QpbzArS1496czo3G3Pa7xfB4Wf7gSptarmynrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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