SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87471f71b89fbfe2edcc0f949459fec9af6c34a9b88110ed77c61810fe45c258' 
  AND token = 'SRrs9A/N+A3SjQj61iEwfJ+XVy6pj4bKebrAql7uhTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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