SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb4f179f28b4938e5e2f5630a04a10128564d1ef17f989146b09827cb83c7950' 
  AND token = '56YCc+ZCv38YCUtALU4oXKR75/Nz3pGvOUHJBuV1KJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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