SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f9fd0604c4a774ec888d1df2fe63cfcd4b216a63568f60ee72d0f855e507725' 
  AND token = 'jDLVLRKoGwZxBBrOAbNwnbihKxGh8uEpd0U1TzF0+MQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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