SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd75b40be295940900fb431636c1200ae4d7781008960e2b678499b5d36da4a0d' 
  AND token = 'b7r0jiAq3L8YpLO5SAYAD7ubtLpt7RKnR/Aadg4o0kc=' 
  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