SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76ca8f6de02aeb4dc96dce75f1506e561e1f531ea09cce3cd5014d38c539747b' 
  AND token = '+VAL9tksNXDObTIBEVFGfF7WPVj+szzSmVYDC3Nc3uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

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