SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760c862961fe986294d9c791cc8131e90632342afc1bfa06648a439b23b267b1' 
  AND token = '7pkCMM4V8BFbmCw/YO0e8x87FflqOG12APT090PuGnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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