SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f21e581f5c3883ee347314403d7e8d3593dacf72b39474d2edb82ab100d965d' 
  AND token = 'UBUkd18dd0M0M+CtMO2Eikf1qzawXKXUo3erkIts/2I=' 
  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