SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb3694ee890d63805a6b009cbf587ff288a9a55ea40cb048024436a52cfff92' 
  AND token = 'Kqp41ixyjnxPucScmR51IGUnB1osTrX7VA6iC+skOp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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