SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931f92a8d3e0d44a66cfccc107abcd90068d9ab95f692ee87c80b753e9bc37ba' 
  AND token = 'IxlK28LU7HydIATSHZTch/xPrQKNZUwIY9vAOUKRV9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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