SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e48fd23f77090711141b579f20efb1c1a56b43488236d726554c67b9a50a0bf7' 
  AND token = 'Yu0ClI0bdeX2wEyMmjeV87iIeXvCbmcT3eGqb/kJBr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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