SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6898a1e6815abafbc06b9ba8a476ad11f515c089c777ce6d0098e9b1134fb75' 
  AND token = 'Le6gnpEIMFNtGsgqQl5N7Zan05JccFzxR27q1LehwX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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