SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1c578f041507a4fb114a754dd7a0211d6d1ef421e6de4b0968dc2c61c2acb1' 
  AND token = 'z41cAreK+M+m/Lld3/tlvTqR4DjPzCRZmeHGNPoysTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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