SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5743c6a233e2bae6e0ae72102c14fbc0c2612c56f37079e3fa9fa8cf8147a9ba' 
  AND token = 'nvb/o0MQuUUfZCOXrb1qlEgVbksC/1mtJZ/zQ1Jxvmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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