SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ac9f3802f0ac2b9bcb5307048235199f29f7e344fbdd28d48f8c626d92b8e0c' 
  AND token = 'jDIfoRTkyCdtI6mFLszeAya46Ks5a91pjTLOky5k2kY=' 
  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"
    }
  }
}