SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a8498413e5c8ae9e437e3a3cd06bb2205f80ea9edbf8b306009840c9056b5ce' 
  AND token = 'NSrrARjf6SCeWtRALiwu+l3jJ5vsT+nBs4LhwdQtTIY=' 
  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