SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f126c19e69beda949698569c39800872d7feb0085ddd5626d86c900b97a79fa6' 
  AND token = '00+i7E/YAF0PGs2MZWNuvlKAx38kbhLEmRNnULnuSD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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