SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '289a6dabf74ab0b7070e7793ab2aba863b0d3ac31d2d29bbdfaf780dbbec4bd8' 
  AND token = '4dnaW+fUjfrY4noqHOe4frmiabg3aQ/NJ11n6u6SwK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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