SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9905ec50f96874a5369bf8dc798b634f80d6387bf8d3b6fb69d03b18392408b' 
  AND token = 'IPeCf7LS0XyhEdwzeMVcMYWL8y1HbAld1NmgWre2230=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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