SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0546263e76721082eb160b156880a82f2a76fb652de03cceba2f71593e0f3713' 
  AND token = 'SnmJvuerBF5qOd+ek/pFpkr8MTFV2M14a6XjYoILWTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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