SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '879f623d4fae14baf5d2de75a863f5543cd0a24520da7ed454025cc224133f6e' 
  AND token = 'nEcuk4tDjCyc+hrQplmzkZCPawAp0eXM+HDM22AIPgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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