SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b984f56d753732835d4991b94394ae395e3efaf012a28fe1ecceb945e1e1fc3' 
  AND token = 'yhcwoolVldN7OTVDpHI7Za66i/Qm2BOkEQxgOJGdt/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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