SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '4c81faff4fde495197e10490a09e3bb44315228deacfe849dfaf5c6ce3b20322' 
  AND token = '5O0UD/Cat+6I8CyFIaOprrsVbYGJQLghXtBb1zzcmBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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