SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8401dee1911ddcc0a3d177600a3a744c74ab0cafc1aa1dd8f59516614ef02fae' 
  AND token = 'codmUjsC5T2YUDikWrtkqdux+1UUWo+SLpgtRjLj9YE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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