SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '286ef71d60f77e5f7498eb4badcaf6e37cb05e6451cc5567613a851a4aa99f91' 
  AND token = 'Y909RhhdVj01MW+48ekCgtRsUVJ2M/Z/B6Xi8z6nGMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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