SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc5597ad3a6c001f2c824f58838652cfd1703f7bb0af25e2f2dea8f9aaf916c3' 
  AND token = '7O3h/OpiCPz4ggcSUD+1Upsv221EgzYbp2zzLZmyFms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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