SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4c0299f6df6a0336c6053601c25b6b52c3fe50ea7abf1730e6686dbabb1dce5' 
  AND token = 'q5V9nY9y0hqWwi6PgYgi6eJhnQF+ndl7DzmiwvbUgq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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