SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db69eccdf16daf029b16e31282a9f3b6ddb4a547b3b7df752d360f9beac8def3' 
  AND token = 'tUQ8LKdixzdEufU59j6dTh0Gf+wkjv9Fx6NOEEPIhJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

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