SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '6f79aba1851afaf945c7c96dd2e6642dc3d3a0f679b2f428c593522f09f11599' 
  AND token = 'LgbcsuKmvxlObDrQAi3t56B1/+95DqcQdU1rKB7dxhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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