SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d43939976cd9dbff203aa159ee6842b9d65965fa7a2257a21f9636879ae1f95' 
  AND token = 'EYBcGpz+AUCoh5Hsarh6gDOPKJH26IAyVKlIM5IykPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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