SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad37b09a857fcaa65c25b76f691720783548f34008d4d333c1f837a6bb3c9d20' 
  AND token = 'A4IMyEvoB1E6XU7Osy+0XRlRhzBsLG+hYgsERrHMTRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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