SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caac4fc4ed8804ddab07244385d854a78a185ac37fd412bcec192682482af463' 
  AND token = 'ksc/nGYLDZWJe6MP1FqUxSDTIEe9TnP7f5z4HxJn1BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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