SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb11be455eab8968bd6458800e6b973d8d3d92f20a0ea0aecc7b479b01158dc8' 
  AND token = 'HPH/L6vkaB4CIH83KK1zTqJC60LKIgeQ+rN8SOwE27Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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