SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64b63ffd939df09cc67b8859302e9143da85d5874eb281fe9b736e819964b6db' 
  AND token = 'g+2x1p8T0TWQL4yFSlBdTAFDqZnpFjJbVzJiGeFUCvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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