SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3336176ef51d500af1bddd6aab478599fbe04824b4ff57b06f0c2acc6fbe2365' 
  AND token = 'b1ZbUZ6DAk9jYEbzP2Cc34BniOt26RoksUvaTcefaFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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