SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dc1f0704d231b80a2683ec318652c460fa577790134b902d94bdcb5f100e355' 
  AND token = 'QAuIgrvHSNv9XOyvh5gUMmiHqb3gsqpVtfr0KaVTCUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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