SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83d95d5ed59058ff3a68408f1a43bebc84a7e0375e084cd4b60f61ffaff757c9' 
  AND token = 'hW42nrePMKYUsohj05SR/Fu2FQufnA4RgppuH7XBOtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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