SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b614c3d3ba108b5db23c4219e8c4101eecb36a13286529b5fc0abaffa0b1d6be' 
  AND token = 'ouuvuZoeWqgC6Acjxk+ieUbzQxgHFu0whI3zpEk0TAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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