SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ac8013a51dd5205eb3184eaa637471ef4fee2bfb8d45b132b5297184b51088' 
  AND token = 'bHou5jArqaiuzq62Y+Uza+ynTitSrLG7jutwZ3FAeEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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