SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d8c39a1d63b838e1a129491d49e0342a39b51e80adf3fa2c38b23bcc7941976' 
  AND token = 'nj3kWoZKUVaY8vnQ8RhdwGOzj3ORlhMmXPZ4UEdGsiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}