SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94f4e986fb531eebfb13778ef222fbbbfc57c230389933a16ec91ef897ab3b69' 
  AND token = '0ZqCKywvZo/TqAVPdAfuw3DmidFGqSy8JmmiZR+TGhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00092

JSON explain

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