SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '6fcf9c75382de07b68c738745fbf12f8157cf64880345a6e70cea637e53f52dd' 
  AND token = 'xuFnQAOGAzv5zRgPWdIXv6Z+r5eVoxybgaTymI75pjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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