SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f06a8c37303411030fe97cdbc4cb257ae9050366ccb2177bea5ba3830eb67343' 
  AND token = 'H86PBgG1l6ZeWTMA1FCghdnN5/Ja2Dr8D2LYvKCYPR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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