SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b12e13c8e76d942bd749fa6abef9208d45e3a26b757560dda461c9fc91e7495' 
  AND token = 'B0UHJOBls2g+xwCrmzKbyKm/HZs2/1+9haff7q4MsyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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