SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8987a18b1a12d68d15e47bd5893f8576da37486221b607401550b3456a0287a' 
  AND token = 'kiyOp0ri7wOTrPgrG6nqyLQnJ1PS7czS/9H+cAc6DGI=' 
  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