SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae435a2e9dab29aac5cfd43984f828e6d4a85a4b3eadf882e4da0bed7d951c50' 
  AND token = 'hYq0w29zOBHnlEM4byQqhn5ivd1u3GNr+5VDPYLVChc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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