SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'a4e0ec19504d6217a1e8367968559e412e87900ce257f8cbd51afb041dfb64b0' 
  AND token = 'VA8LbdvH+nIahszHZFtxKKYdfyVTgzL0rypXwahtr6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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