SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '631d39e4a86ea7e7ad1f731159eb6a84b30f4f72891c6f7be2a85c099c46a1af' 
  AND token = 'RqjvQV6ziJfvQHsJqYIl5AFTKgjkftT2//JgKFTxLTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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