SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '12c2715cca4d5786a98eb9f65258fb01e518d7664c62d5bd03b1bcd9d0477ca1' 
  AND token = 'MGesxPrtpNYA7YscBM5XnzgosBxMkm/OlAdnLaMLkPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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