SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f1bb2c3c0de856611dca950338c6b0e7924a537645b46a25523fb04371293f' 
  AND token = '51B+bqs1HzK9/jjIyomDfQg7ZxuiYSr0N+6ZbFgvnPk=' 
  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