SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b58f6ef8fd4eb34c49a7bcb6503e949720101d428ff476d2aa1798f90be9a07' 
  AND token = 'kt0e0ih2CbCNSwHjWMBGMFqgHDQ3KgpyZoWHEhmxolY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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