SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ab26b1e1bfa276325067c0fde9fbc65a02647b78bc9d4ed379c9e50a694f41' 
  AND token = 'VRgaNR7Rdlu3+8DGP3o1mv6ULVBGQcu11Dv+6gtPJuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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