SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '563f51220b1f377c9015e92854368bf34366ac7a7780bbdf2aa47b23280f2a64' 
  AND token = '3Q6xnED7N/RZ+gFwTBcsf9beWpk7c2Ym90OF+Z1WITA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

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