SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54bf49e4bb915ba35a0f82f6e3de56248b67f49d2eefdffaadbaa8fd7381d718' 
  AND token = 'lWTxInyDDeyDcPMJMx91FRrNwg4P5LfBa/V1oi10sA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}