SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'b99ea1e60199be25909c6ad711210ad447736cb05c9ecd6a938f0037be0fb5d8' 
  AND token = 'QhZAbjBQfV1mU7vWeP/eIEIEwjk04Mhw2x+gVk3CJKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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