SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d5e3dfb1b34e99cfb472d1e0b9078740556c1cd6b9e843538537ceab36f6b7d' 
  AND token = 'i47vebUNyK8wbTP7e7xqNr09LMPMfHIgjbJC/IJwWlk=' 
  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"
    }
  }
}