SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70642f0237ae051463ea55658853fd607580fbf23c430fe8ff8c9c78aeba8391' 
  AND token = 'umHl7GDpdmuiQuu6CcEGxu+tPBaasDmMLtmsR6nmFc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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