SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96a0d1a4e5a1cf642aa051fdca4383380f53df29004fd40193969e39cbeb7df' 
  AND token = '5veZhG6nKmGBBS1s3iHBGMrRbY5u5I2Kx+2DJn6Aas0=' 
  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