SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a26e9c69a1866cecf0de99506f0714fcaff5039c349fcd77ed2a1b382188265' 
  AND token = 'cOtsLERUybj37QcYyZMH9361mi/huHzelJun5giBggI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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