SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e2b4d5f7c405395c0dd39eefaa70161c49f7ec275d6830365a9d0e353a0a914' 
  AND token = '9fedlspHH+aBLOH/sgjaivSG1jB13g/y0P5JJ8Quy7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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