SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7467127d453a0811c8d13d79cd71f8bb02a1e9c35f825a0350941e5918641a0' 
  AND token = 'Qd/18pBh62qzWyuamYlgeD38vvegBf2HT8G7Pj8zMmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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