SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f502bf621cfadc252ee55c2a1c59a0a899d1162558ab202e4fdfdd0a6b62daa' 
  AND token = 'a80KSsWC3c8jgt9Tuf7ehnVxCoc6X/OzTxXP764nzxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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