SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3dbcb7cf129ebda2958dbf2f35a74e16197096b71016f161ca95cedc8b10184e' 
  AND token = 'BGJyDcQksVCvKYxkYdOlhKBUMxgcIkuqOZcipdADmIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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