SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54843a3d23c2f2cceef997ed51df9c6f0d771d3652b0ac5fe85cb55820bcf9b1' 
  AND token = 'AEk6eVWDy83sGcVcBoFY2e8q9+ODoYwJ6+DpCtbZKR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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