SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '994a446612c2daa1e15cb02d5ac08af87284917836181b568da5d7572d6f1368' 
  AND token = 'pOBpmk6WJ0gZKnzPGcFFHIVSVk9JITAOTxLGlg3jXXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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