SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '588a78b1683bd58797d7467c20a15ec237bb22cfd0f0a81007f8cce1fc9a93be' 
  AND token = 'g/8zFnmt52ftYy7iWW9BMmQ1VJhguvBA2IBMfCwH/NU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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