SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f02b95b71d817eaf07784439a2a37cca397683d3c4afb9fca3417bec8240684' 
  AND token = '6aoohUDAOyJ7tXuTBlar2Lw9f2CLtHAk6mm/dBErFt4=' 
  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