SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28d754bb124c8ce8e296884c286b2d72bb02e5024e4665808502ddb95c4d0928' 
  AND token = 'UXIxPKkZp7+AOR+2+QpjFHWHtQWW5zXgvLnKda7SBpQ=' 
  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