SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e467d87aef6752e9e464a06240237813a414a3bba5571e25a78d0e1217fb1c16' 
  AND token = '7bxVjMYII9/WaoN4yNi6bPGJexNHe/z/MgF9peKgSSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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