SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ca7c8aec1ecbc9fef351c7ffcd7c867eea946c1a914da9964fbcd924ee5d3b8' 
  AND token = '1ex2VpP7Vo8HxLLbLVZvXljvvhB+JHjPjjJsbZMHavU=' 
  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