SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '463df24245e8448a3d31b628f9dcb95d989d32854159d399d5d3d912d7f01292' 
  AND token = '9TLcQD2Dt25ZGS1wiGDL2scZlprNFzhz1bMrGpPwPps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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