SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a891bafafdb7a7d0df7807e7bfa532893328543c6c9e2eebec86db770dd7789f' 
  AND token = 'j1My0q8tDG2XECTIpxA+p7AvpRX138m43Vy19yW9Dqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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