SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f6f6beea8aee01d06caef950433553e4097e607851a087302a862782138e81' 
  AND token = '1RNxVSbjx8Kuc8FjATFyS1fqafU9/GJoDK83TPpRZjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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