SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f6170472359ef298bf77b28c8e990baa5ad3780046fad001e420125bc548634' 
  AND token = 'cbpOm/Wz1TMBWnbBLDOVqegFiznpbFYcTdSW9e9WoEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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