SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f1ff88929c78bfafb30acec25c59969eeef1db4259a63146da4ae87959571de' 
  AND token = 'g4+UK6mKVfokGxW0LrKTVOxJ6PJZGzd25yrpyDRTBY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables