SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94a42532f0d3b5383e6005e4349408503f52291025aa0cfa17cac5e7656f970c' 
  AND token = 'WHmCNbsmpN/JldXoKvgHUodbIW7gL/uw1s6Ey5AxDhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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