SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeb8d4537f5376e5ea169b71ff49fc9778c6ceaf58b28b6abff090541d9182a4' 
  AND token = 'hD1z5bhewTR/ZGOVvMF2PceteTmCffnnQNJSFl4sVHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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