SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '131ebad38ed4d1fb64d2002f7a36535b8418b40bf9205a5216379b53a439c7f1' 
  AND token = 'PaZPZ81yTubH3Lu53cX9tiDQK3lLvT2iYxF1p79o1iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}