SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deba9e2538b917d8140eefeb07ffdf4ee259165d668fd148625fdef8713fea92' 
  AND token = 'ncnRebuRCNvd133wK73cEEdncUNgxB0KWorxe4Vp/mM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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