SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc1d3c4bdf21db445e890909fe7036fafc8b4aad6b84c0f63cf3ecf4c3512059' 
  AND token = 'lzy/PkyM7fnPFPgL7yRZ5tr3tMuv1qnIboTmBRMceVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}