SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5952b98018c9cd8905334eb1be12c950b30bd56f89fdf40a933d6e981c4ec0cb' 
  AND token = 'u3ODC3+4fJ+IAOtSWnPyzzzjl/r7AZoORWkYN7sVIfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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