SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '937219560330fc044d6c49a3d21bd0b92dbc3328004e960451f1db663b94f431' 
  AND token = 'WODQrayuQ7qi5So1kCCrn0GORAI+CYc7IiLVUiotrwY=' 
  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