SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52dcbd8e05b206851ab4b808dfcb3b99083c0187c18c18541b63d878b792c7d1' 
  AND token = 'WPiUuAryLXCEt7kt/EWKpguwFsMy3CZavYR/fq2lnY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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