SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4aa87253a728b1cfae92469aa82a06f7d43cbc73a1d5303084b9d257463e3f2' 
  AND token = 'PtfYQR6hRbgdng0LAGSzcYkCiCNMbO9yBSzoetEusSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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