SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef5c72848b6246719c7cf1a541ee9a011a43cd4c2ce11089bac7db3e8e63cd5a' 
  AND token = 'BZzKqngYvWCLHOIY32FJt/uGrwMB37fr2U+E1vYbSqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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