SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4afe2c25d0059378ffa88f27b55ac487088cf38e37cc4268ae1539d0355b9499' 
  AND token = 'KEUtKnJjuHXUA6voAFcGV5iUjY5nBeWkvvf+zegp5VI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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