SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcd2513269b67e415b24362093fe59e4e3b02a1bfb7518317021265732016976' 
  AND token = '/YgmZjYehieYPkABhCrdnYPK8EKiklce4TQKmxcDi8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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