SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcaedd034da77b064fe205467686bbe1bc419fb6fe11cb78c61dd8259247c9bf' 
  AND token = '9xXmp7SVFYHD4iYuNzaHqWbkctgBFnLHfCf0b3c/MGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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