SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5022957e81a83b21f90530bd0ba5e11b1c86581b1750eb0aeb524c88f8a2466' 
  AND token = '5Gtu4JOa4cu5DORA2YgIyMCrqDouB5AZc5iZ9Y8Mbxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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